The surface area of the Kattegat and the Skagerrak, located in the eastern North Sea, is about 22 000 km2 and 32 000 km2, and the mean depth is about 23 m and 210 m, respectively. The Skagerrak and the Kattegat forms the inner end of the Norwegian trench, which has the characteristics of a deep (700 m) fjord connecting the Baltic Sea with the Norwegian Sea (e.g. Rodhe, 1987). The sill depth of the fjord is about 270 m. The Kattegat offshore and inshore waters were identified as problem areas, whereas the Inshore Skagerrak waters the OSPAR categories I - IV indicate a slight incoherence in the assessment, although with an overall judgement to be identifi ed as a problem area. The offshore Skagerrak was identified as a non problem area, according to the OSPAR Comprehensive Procedure. (OSPAR Commission, 2005).